How to Choose Which Scale to Play

In this tutorial I'll show you how you can develop a better and solid solo using your knowledge. I'll show you how to develop better improvisational skills. I'll look at a number of approaches and I'll clear some of myths you may have heard over the years.

The Number One Rule

Given a certain chord, you can play (over that chord) every scale that has the note of the chord in it

This has to be your mantra, from now on. Well, what I meant is that it is this perspective that I personally find the best to write solo or to choose scale in general.

The main principle is that the chord comes first. The more the chords is defined, and by that I mean that has more notes in it, the more narrow the scale choices will be.

Key Center

To be clear on what this means, Key center is the idea of grouping all the chords of a progression into one key. For instance:

That's the key of A natural minor, Aeolian. You don't think about every chords separately, instead you see a giant block of A natural minor.

Another example could be:

This time I have an A Dorian progression. Same mindset as before: you can play A Dorian on every chord of the progression.

Using this approach is straightforward, but consider the pro and the cons:

Pros:

Easy to use because it doesn't require lot of thought. You just need to find the key and then you can jam over it

Appropriate for generic pop/rock/metal solo

Cons:

It doesn't emphasize the chords you're playing over it

It's a static way to create interesting melodies. It gets hard to make your instrument really sing

Here's a final example of this progression

I'm using the A Dorian scale over the entire progression.

Chord Scale

This is essentially the opposite of what I discussed above.

Don't consider a progression as a box with lots of different chords in it. Instead you analyze and break down the progression until you can refer every chord to a specific scale.

This will require some basic theory knowledge.

Consider this progression:

I added roman numeral below the chords: those are the degrees of the chords in the key of D Ionian, or major.

As you can see D is the one chord, A is five minor and so on. I want you to think about the modes of the major scale that I have compiled in this chart.

As you can see the mode build from the first degree of the major scale is named Ionian, the second Dorian, the third is Phrygian and so on.

If you now connect the roman numeral of the progression to the modes of the chart you will end up with this scale choices.

On the D you can play D Ionian (D major). On the A, which is the chord build from the fifth degree, you can play A Mixolydian. On the Bm you can play B Aeolian, and on the G you play G Lydian.

As I said earlier this approach requires some extra theory knowledge as well as some scale knowledge.

You may have noticed that D Ionian, A Mixolydian, B Aeolian and G Lydian are all the same scale just named differently. They are, note-wise at least. You might consider the advantages and disadvantages of this approach.

Pro:

By thinking a scale from the root of the chord that is played behind you will surely create better sounding motif, that will emphasize both the chord and his extension at the same time

Appropriate for tons of genres but much used in jazz and fusion

Cons:

Hard to digest. It requires knowledge both theoretical and scale wise. Unless you're very good at theory this won't be the fastest way to improvise on a progression

I'd like to outline the advantages of using chord scale approach since I personally found it hard to understand at first.

The hardest thing when playing guitar is achieving the skill whereby you're not played by the instrument. You should always decide what you play based on which impact will have without falling into a sort of noodling move on guitar. The moment you forget you're making music and not an exercise, the music dies.

The mindset offered by this approach is unique: in fact every time you will have a new chord you will mentally refer to a new root in your scale even if you're always using the same note.

Even if I'm playing the same note on every bar, every time a new chord will appear, that note will have a different color. I need, as a player, to visualize that note differently every time.

Here's an audio sample where I play over the progression with discussed trying to highlight my chord scale choices:

Chord Tones

Chord tones is a mixture of what I talked about above. Chord tones are the most important notes of the chord. You can easily identify them as the root, the third and the fifth. If you have a seventh chord you can definitely think of the seventh as a chord tones.

Those are the most important notes because they spell out the entire chord. This concept is express, technical wise, with arpeggios.

A great knowledge of arpeggios can definitely save your life nine times out of ten. But this approach doesn't only refers to arpeggios: in the end you do want to expand your possibilities and choices. So this is how I use the chord tones mindset.

You need first of all to know your arpeggios well. Then you need to be able to switch arpeggios both staying in the same position and moving up and the neck. Once your mind targets instantly the chord tones, you just need to use the notes in between as connection. If you try this out you will get very chromatic. At the same time, although, you can decide to remain more diatonic and use just the diatonic note when moving from a chord to another.

I'll show you what I'm saying by soloing over this progression:

I'm going to use Am arpeggio, C major arpeggio, Dm arpeggio and E arpeggio. And of course all the notes in between.

Take a listen:

Conclusion

I recommend that you to read this tutorial step by step trying to spend a little time on every approach I outlined before moving on.

None of those are easy and in the end they all are tools that should improve your playing as well as your confidence on how to approach soloing.

Now that you have the guidelines, experiment with them, break the rules and go writing a killer solo.